Unlike conventional hydrocarbon dispersants that rely solely on the single working mode of hydrophilic-lipophilic adsorption, fluorocarbon surfactants leverage the ultra-low surface energy of perfluorinated/short fluorocarbon chains, unique molecular structures and dual compatibility properties to achieve efficient dispersion and stabilization through four core mechanisms. They are compatible with various fine fillers including pigments, talc powder, silica powder, nano-silica, nano-titanium dioxide and functionally modified powders.
The surface tension of common solvent and resin systems mostly ranges from 30 to 45 mN/m, while the surface tension of low-surface-energy powders is below 25 mN/m. In accordance with critical wetting conditions, the system cannot spontaneously spread and infiltrate the gaps between powder particles. Air is trapped inside powder pores, forming hard agglomerates.
Fluorocarbon surfactants can reduce the surface tension of organic systems to 15–20 mN/m (short-chain PFOS-free grades can reach 18–22 mN/m), breaking the wetting barrier at the solid-liquid interface. They rapidly penetrate the interstices between powder particles, displace entrapped air, completely disintegrate primary and dry agglomerates of powders, and fully wet powder surfaces, laying a foundation for subsequent single-particle dispersion.
Fluorocarbon surfactants feature an amphiphilic asymmetric molecular structure:
The fluorocarbon hydrophobic end firmly adsorbs onto the surfaces of low-surface-energy inorganic/organic powders and nano-fillers to form a dense monomolecular adsorption layer that prevents desorption of additives;
The hydrocarbon hydrophilic end exhibits high compatibility with matrix systems such as organic solvents, acrylic resins, epoxy resins, polyurethane resins and alkyd resins, perfectly bridging powders and resin media.
This mechanism addresses the drawbacks of conventional dispersants, including weak adsorption on low-surface-energy powders, easy desorption and poor interfacial adhesion, and avoids secondary agglomeration after dispersion.
Steric hindrance stabilization: Fluorocarbon molecular chains adsorbed on powder surfaces form a steric hindrance layer of 5–20 nm. When powder particles approach one another, molecular chains generate steric repulsion to counteract van der Waals attraction between particles and prevent particle collision and aggregation.
Auxiliary electrostatic repulsion stabilization: Ionic fluorocarbon surfactants can impart uniform electric charges to powder surfaces and create electrostatic repulsion via electric double layers. The combined effects thoroughly eliminate flocculation, sedimentation and delamination of powders, greatly improving the storage stability of the system.
Nano-powders and ultra-fine pigment fillers possess large specific surface areas, which readily cause local polarity imbalance in the system and trigger regional agglomeration. Fluorocarbon surfactants can be evenly distributed throughout the entire resin-solvent system to balance interfacial polarity, eliminate local surface tension differences, realize uniform full-range dispersion of powders, and ensure consistent color and homogeneous performance of finished products.
This formulation is applicable to solvent-based resin systems and mixed solvent systems, covering conventional pigments, functional fillers and nano-powders. It adopts environmentally friendly short-chain PFOS-free fluorocarbon surfactants (complying with national standards and EU environmental regulations) to replace traditional long-chain fluorocarbon additives and ordinary hydrocarbon dispersants. It resolves agglomeration, floating and sedimentation issues, and significantly enhances system stability and dispersibility.
Resin matrix: 45–55 parts (acrylic resin / polyurethane resin / epoxy resin, selectable as required)
Mixed organic solvents: 20–28 parts (blend of xylene, ethyl acetate and methyl ethyl ketone)
Fine powder fillers: 15–25 parts (pigments / silica powder / nano-silica / titanium dioxide, etc.)
Short-chain fluorocarbon surfactant (core component): 0.2–0.6 parts
Functional auxiliary dispersant: 0.3–0.8 parts (polymeric wetting dispersant to further improve resin compatibility)
Leveling and defoaming additive: 0.1–0.3 parts
